Self actuating self locking flexible hinge

ABSTRACT

The hinge is capable of twisting and bending about at least two axes and comprises a pair of strips having a transverse curvature. The strips are secured at their ends to a pair of rigid tubes, beam parts, supports, and the like, which are thereby joined together. The strips are preferably mounted facing one another with their centers of curvature lying inward. In bending the hinge, the strips are caused to flatten out and the inner strip is compressed thus developing the actuation force. Rubber pads or the like may be placed between the metal strips in order to increase the stored spring energy and to improve the hinge&#39;&#39;s folding characteristics.

United States Patent Schwartz et al.

[ 51 June 20, 1972 [54] SELF ACTUATING SELF LOCKING FLEXIBLE HINGE Hughes Aircraft Company, Culver City, Calif.

[22] Filed: April 29, 1970 [21] Appl.No.: 32,945

[73] Assignee:

2,211,385 8/1940 Preston .L ..248/21 Primary Examiner-Bobby R. Gay

Assistant ExaminerDoris L. Troutman Attorney-James K. Haskell and Lewis B. Sternfels ABSIRACT The hinge is capable of twisting and bending about at least two axes and comprises a pair of strips having a transverse curvature. The strips are secured at their ends to a pair of rigid tubes, beam parts, supports, and the like, which are thereby joined together. The strips are preferably mounted facing one another with their centers of curvature lying inward. ln bending the hinge, the strips are caused to flatten out and the inner strip is compressed thus developing the actuation force. Rubber pads or the like may be placed between the metal strips in order to increase the stored spring'energy and to improve the hinges folding characteristics.

3 Claims, 9 Drawing Figures PITENTEDJuuzo I972 3,670,358

sum 1 [If 2 Charles F? Rubin, Se our 8. Schwartz,

VENTORS,

ATTORNEY.

PATENTEDJUN 2 0 is? sum 2 or 3 SELF ACTUATING SELF LOCKING FLEXIBLE HINGE The present invention relates to a self-actuating, selflocking, flexible hinge which is twistable and movable about at least two axes. i

The conventional hinge generally comprises a pair of plates joined by a pin to provide angular motion about a single axis. To obtain a further rotational axis, a form of universal joint is utilized whereby the second axis may be pivotally extended through the first at some angle thereto, generally at right angles. Other variations or additions may be included to provide further degrees of motion. In all cases, the joint or hinge becomes relatively complex and requires sufficient manufacturing precision in order to permit proper operation of the hinge. To obtain locking thereof in any one position," special locking means is required, 'which adds further structure and further increases the cost of manufacture.

The present invention is directed to a hinge which is simple but permits a large degree of movement of the two elements connected by the hinge. Additionally, it enables locking of the two elements in a particular configuration of the hinge whereby relative movement between the elements is inhibited. Briefly, the present invention accomplishes these objectives by utilizing a pair of transversely curved strips or bands of spring material which are secured at their respective ends to the two elements to be joined. In one embodiment, this curvature presents the strips with concave and convex sides. Preferably, the strips aremounted in such a manner that the concave sides face each other and are mounted 180 apart. When the strips are unbent, their curved transverse cross-sections resist bending and thereby lock the two elements along the longitudinal axis of the hinge. Bending of the hinge, however, is easily facilitated by moving one element towards the other in an are, thereby bending both strips against their normally curved cross-sections. In this position, one element can be easily turned or twisted with respect to the other element to provide a degree of motion about more than one axis with the additional facility of twist capabilities. To improve the folding characteristics and to increase the amount of stored spring energy when the hinge is bent, an elastomeric substance is placed between the strips.

It is, therefore, an object of the present invention to provide a simple hinge.

Another object is the provision of a self-locking hinge.

Another object is to provide such a hinge having at least a two axis rotational capability.

Other aims and objects as well as a more complete understanding of the present invention will appear from the following explanation of exemplary embodiments and the accompanying drawings thereof, in which:

- FIG. 1 is a view of the hinge connecting a pair of elements in its locked position;

FIG. 2 is a cross-sectional view of the hinge of FIG. 1 with an elastomeric pad placed between the curved hinge strips;

FIG. 3 shows the two elements moved from their position of FIG. I, causing a bend in the hinge;

FIG. 4 depicts the hinge and elements fully bent;

FIG. 5 illustrates the twistable capability of the hinge; and

FIGS. 6-9 depict'the use of the hinge in a foldable and unfoldable torus, the folded or stowed condition shown in FIG. 6 with successively unfolding through FIGS. 7 and 8 to its deployed state in FIG. 9.

Accordingly, a hinge or joint 10 comprises a pair of strips or bands 12 and 14 of spring quality material having a transverse curvature as illustrated by radii l6 and 18, respectively, for strips 12 and 14 (see FIG. 2) to produce a convex side and a concave side 22 of strip 12 and a convex side 24 and a concave side 26 of strip 14. Strips 12 and 14 are secured at their respective ends 28, 30 and 32, 34 to elements or members 36 and 38. The members may comprise two segments of a tent pole or the like, antenna struts or booms or reflector supporters, umbrella elements, or any other straight or curved pole, ring, or the like which is required to be folded and then extended or deployed, for example, when the device utilizing the hinges must be transported in a stowed condition and then unfolded when required for use.

In its configuration shown in FIG. 1, elements 36 and 38 lie along the axis of hinge 10 which, because of the transverse curvature of its strips, inhibits movement of the elements from their axial disposition. However, the elements may be moved toward one another as indicated by arrows 40 so as to cause hinge 10 to bend and the are or curvature thereof to flatten out, as shown in FIGS. 3 and 4 as the elements are progressively moved towards one another. In the position of greatest folding, shown in FIG. 4, the bands are at their greatest spring tension and are flattened out and act as bent leaf springs. If the elements are not restrained, the stored spring energy in the bands would move the elements outward to the position shown in FIG. 1 to provide an automatic deployment or straightening out thereof. Therefore, some form of restraining mechanism would be required, as is well-known in the art.

FIG. 5 shows the ability of the elements to be twisted relative to one another, as shown by arrows 42, because of the relative freedom of hinge 10.

To increase deployment energy of hinge 10 and to improve the folding characteristics of the strips, pads 44 of an elastomeric material, such as rubber, as further depicted in FIG. 2, are placed between and in contact with the two curved metal strips. When the hinge is bent back upon itself as shown in FIG. 4, additional spring energy is stored in the elastomeric pads which add to the spring energy stored in the flattened cross-section of the strips. Furthermore, the pads militate against localized bending and high stresses at any one point of the hinge. Thus, bending of the hinge beyond the elastic limit of either band is prevented to insure repeatable folding of the hinge and accurate positioning in its locked condition.

The hinge of the present invention is useful, in one application, in the antenna described incopending patent application, Ser. No. 590,561, filed Oct. 31, 1966, now U.S. Pat. No. 3,576,566, patented Apr. 27, 1971, and assigned to the assignee of the present invention. In that application, the electromagnetic wave energy reflecting surface is joined to a segmented ring or torus. The torus acts as a closed beam and tends to be self-stabilizing so that the forces which arise from temperature differentials counterbalance each other to prevent thermal distortions of the entire antenna. Such a segmented torus 46 is depicted in FIGS. 6-9.

The torus includes a series of arcuate segments 48 joined by hinges 10. Segments 48 correspond to elements 36 and 38 of FIGS. 1.5. This jointed arrangement permits a folding of the antenna into a compact, truncated ogival configuration, shown in FIG. 6, which may be shaped similarly to the interior of a vehicle shroud or nose cone for efficient stowage therein. When the antenna is placed in its intended position, for exam ple, in space or in some near or remote earth location, the shroud is removed and the hinges pivot or articulate under the spring bias of bands 12 and 14 to unfold torus 46 and its attached antenna electromagnetic wave energy reflecting surface 50 from its stowed ogival arrangement of FIG. 6 to its deployed and operational condition of FIG. 9, through successive unbending shown in FIGS. 7 and 8.

Because hinges 10 are provided with a rotation in two planes, as torus 46 unfolds into its deployed operational condition, hinges l0 permit segments 48 to be placed in tandem and guided into the circular configuration of FIG. 9 by means of the rotation in two planes.

Although the invention has been described with reference to a particular embodiment thereof, it should be realized that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

l. A self-actuating, self-locking flexible hinge comprising a pair of strips of spring material, each said strip having a curvature transverse to the length thereof to provide a concave side and a convex side, said strips being positioned apart with the concave sides in face to face relationship, means joining said strips together at the ends thereof, and an elastomeric material placed between and in contact with said strips, said strips twistable and bendable about at least two axes when said strips are curved in a direction angled to the length of said strips.

unfolded to lie in a single plane, said unfolded loop thereby acting as a closed beam, and articulated lockable joints secured between said segments and to adjoining ends thereof, each said joint comprising a pair of strips of spring material joined at their ends to said segments and elastomeric material positioned between said strips for unfolding said loop and for twisting and bending about at least two axes. 

1. A self-actuating, self-locking flexible hinge comprising a pair of strips of spring material, each said strip having a curvature transverse to the length thereof to provide a concave side and a convex side, said strips being positioned 180* apart with the concave sides in face to face relationship, means joining said strips together at the ends thereof, and an elastomeric material placed between and in contact with said strips, said strips twistable and bendable about at least two axes when said strips are curved in a direction angled to the length of said strips.
 2. A self-actuating, self-locking flexible hinge comprising a pair of transversely curved strips of spring material, said strips being secured to each other at their respective ends and mounted facing each other with the center of curvature of each said strips lying toward the other of said strips, and an elastomeric material placed between and in contact with said strips.
 3. A foldable and unfoldable closed loop including a plurality of single segments placeable in tandem when said loop is unfolded to lie in a single plane, said unfolded loop thereby acting as a closed beam, and articulated lockable joints secured between said segments and to adjoining ends thereof, each said joint comprising a pair of strips of spring material joined at their ends to said segments and elastomeric material positioned between said strips for unfolding said loop and for twisting and bending about at least two axes. 